The revival of this branch of the ceramic art has given rise to a purer taste in all that concerns domestic decoration, and induced ideas of cleanliness unknown before.
The modern mode of making encaustic or inlaid tiles is first by modelling the design from a drawing on a thin film of clay on a plaster ground, or by incising the ornament on a block of clay or plaster, and then pouring over the model, plaster of Paris to form a mould. Moulds from a hard plaster or a carved wooden model are sometimes made in brass, and a rnetallic frame is often the boundary of the plaster mould. Metallic moulds for patterns which are to be much repeated are the best and most economical. The clay for the hody of the tile is pressed into a mould by a small screw-press ; and the mould produces the outer fortu of the tile, and the ornament on the surface, at the same turn of the screw. After the tile has been pressed, and removed from the mould, it is allowed to become tough in dryness, before the operation of filling in the indented ornamental sur face takes place. When the tile is thus far dry, a thin mixture of white, buff, or coloured clay is carefully poured over the indented parts ; if two or more colours are to be poured in, stops of clay, or coverings, are used to check the running of one colour into another, and the respective colours are thus filled in one after the other. After filling in, the tile is placed again to dry, and when very stiff, it is carefully scraped over with a thin piece of steel, and all the coloured clay lying unevenly on the surface is removed. The ornamental features are then seen in sharp outline, and the tile is thoroughly dried for firing. There is a disposition in some clays, when so treated, to round on the face in drying and burning ; this is checked by placing a thin layer of clay of a different refractory character on the back of the tile when it is first formed, and piercing holes through this layer of clay, to admit of the free egress of steam and fixed air. The modern practice is to glaze such tiles as are required to have an enamelled surface, by a second firing, after burning them first in the biscuit state.
Without trespassing upon the subject of porcelain buttons (see Buttons, p. 559), it may here be mentioned that, in 1840, R. Prosser, of Birtningbam, obtained a patent for the manufacture
of buttons by reducing the material of porcelain to a dry powder, and subjecting it to strong pressure between steel dies ; the powder, being compressed into about a fourth of its bulk, becomes a compact substance, and can be at once placed in a kiln and fired. Prosser disposed of part of his interest in tbis patent to Herbert Minton, wbo then made some very beautiful china buttons and studs. In 1841, Blashfield saw them and learnt how they were made, and conceived that the button making process might be extended to the manufacture of tesserte and small tiles for pavetnents. A correspondence ensued between Blasbfield and Minton on this subjeot, and the latter made some experiments, and sent Blashfield some 1-in. cubes, having a blue colour on one face and a white body. The blue colour was crazed and cracked. Minton made further trials, and succeeded in producing some very good blue and some white tesserte, in. thick and I in. sq. ; these Blashfield placed together in the form of a Greek fret on a drawing-board face downwards, and poured Roman Cement over them, pressing &info flat roofing-tiles into the e,ement, and thus formed them into a small slab. When the cement had set, the face of the mosaie was washed, and this first piece of Minton's mosaio work was exposed to the weather during the whole winter, and received no injury from tho fre3t.
Prosser enlarged his patent to cover the making of tessera) and tiles, and began to make machines for Minton's use in this way, and entered freely into Blashfield's views. The latter sug geeted sizes of teaserte and tiles, and colours, and the importance of gilt and enamelled tesserte, and gratuitously provided Minton with designs of mosaic pavements and tiles, and copies of those in Westminster Abbey, subsequently calling to his aid Owen Jones, H. Kendall, and Digby Wyatt, and commencing with them a series of publications of designs. In 1843, the process of manufac ture wae exhibited by Prosser and Hashfield at a meeting of the Royal Society, when the late Prince Consort took great interest in the making of the tessera), and desired au account of the whole subject te be sent to him.